Quick answer

Passionflower is a climbing vine used as a calming tea and extract. In a small trial, a week of evening tea made from 2 g of herb gave a slightly better sleep quality rating in healthy adults, so the evidence is early. It can cause drowsiness, should not be used in pregnancy, and may interact with anesthesia.^1,2,3

Key facts

In the tea trial, sleep quality was rated about 5% better than with placebo tea, and none of five other diary measures differed.^1,2
NCCIH says passionflower tea may be safe for up to 7 nights, and daily extract for up to 8 weeks.³
Five of six passionflower food supplements tested in Europe failed identity or content checks.⁴
Tell your health care provider if you take passionflower within 2 weeks of a scheduled surgery.³

What passionflower is

Passionflower is a climbing vine with white and purple flowers, native to the southeastern United States and Central and South America.³

Passionflower has traditionally been used as a sedative. Spanish explorers learned of it in South America in the 1500s and brought it to Europe.³

Its main compounds are flavonoids such as apigenin, luteolin, quercetin and kaempferol, and flavonoid glycosides such as vitexin and isovitexin.²

In laboratory work, a dry passionflower extract bound to GABA receptors and blocked GABA uptake in rat brain tissue. How it acts in people is still under discussion.²

NCCIH says passionflower is likely safe when used as a flavoring in food.³

What the evidence shows

There is one claim below, graded early. It rests on a single small trial in healthy adults, with two extract trials, one in people with a diagnosed sleep problem and one industry funded, pointing the same way.^1,5

May modestly improve self-rated sleep quality over a week of evening tea*^1,2,5,6

Early evidence

In a double-blind crossover trial, 41 healthy adults aged 18 to 35 drank a cup of passionflower or placebo tea each evening for a week. Sleep quality was rated about 5% better with passionflower, but it was the only one of six sleep diary measures that differed. Two extract trials found longer total sleep time: about 23 minutes longer in a sleep lab in 110 adults with a diagnosed sleep problem, and longer self-reported sleep in 65 stressed adults who slept poorly, in an industry-funded trial.

Amount studied: A tea of 2 g of dried herb in 250 mL of water, each evening for 7 days

NCCIH says a small amount of research suggests passionflower might lengthen total sleep time in adults with sleep difficulty, but its effects on how long it takes to fall asleep and on staying asleep are mixed.³

NCCIH says passionflower hasn't been studied extensively, and there is not enough evidence to judge it for most other uses.³

Passionflower has also been tested before surgery and dental work, where it is given to settle nerves. We make no claim from those trials, because NCCIH advises against using passionflower before surgery unless a health care provider recommends it.^2,3

How much people take

The tea was 2 g of dried passionflower in 250 mL of water, drunk once each evening for 7 days.^1,2

A 30-day trial used 600 mg of extract once a day at bedtime.⁶

There is no official recommended amount. The dosage guide covers the single doses used before procedures, liquid drops, and how long NCCIH considers use likely to be safe.

Tea, drops and capsules

Products use the above-ground parts of the plant, such as leaves, stems and flowers, as tea, liquid drops, tablets or extract capsules. Most trials did not say which parts they used.²

In a 2025 analysis of products sold in Europe, five of six passionflower food supplements failed identity or content tests, while all five registered herbal medicines passed.⁴

That analysis is a reason to look for products that name the extract and state its strength. Our Sleep formula's label lists passion flower extract from the stem, leaves and flower, but gives no extract ratio.⁴

What's in ours

What’s in ours

Sleep: Passion Flower Extract, 100 mg per serving, from the label

Our Sleep formula has 100 mg of passion flower extract per serving. Without an extract ratio it cannot be compared with the 2 g of herb in the tea trial, so we make no passionflower claim for it.^1,2

Side effects and who should avoid it

Possible side effects include drowsiness, dizziness and confusion.³

In a dental surgery trial, half of the people given passionflower reported sleepiness, against 82.5% of those given the sedative midazolam.²

Taken around the time of surgery, passionflower might slow the nervous system too much when combined with anesthesia or other medicines used before and after surgery. NCCIH advises talking to your health care provider if you take it within 2 weeks of a scheduled surgery.³

In one published case, a woman developed severe nausea, vomiting, drowsiness and an abnormal heart rhythm after taking passionflower at usual doses, and needed hospital monitoring.⁷

No upper limit has been set for passionflower. NCCIH says the tea may be safe for up to 7 nights, and daily use of the extract may be safe for up to 8 weeks.³

NCCIH says passionflower should not be used during pregnancy, because it may cause uterine contractions. Little is known about its safety while breastfeeding, or about putting it on the skin.³

Do not use it if you are pregnant³
Tell your surgeon or dentist if you have taken it in the 2 weeks before a procedure³
Ask first if you take sedatives, sleep medicines or any prescription medicine³
Do not drive or use machinery if it makes you drowsy or dizzy³

Apart from anesthesia and the medicines used around surgery, no official source we could find names a specific medicine that interacts with passionflower. That is not proof of safety, so ask your pharmacist before combining it with any medicine.³

Questions people ask

Does passionflower tea help you sleep?

In one week-long trial of 41 healthy adults, evening passionflower tea gave a slightly better sleep quality rating than placebo tea, but the other sleep diary measures did not change. That is early evidence.¹

Can you take passionflower every night?

NCCIH says the tea may be safe for up to 7 nights and daily extract for up to 8 weeks. Longer nightly use has not been shown to be safe, so ask your doctor before going beyond that.³

Why does passionflower matter before surgery?

With anesthesia or other medicines used around surgery, it might slow the nervous system too much. NCCIH advises telling your health care provider if you take it within 2 weeks of a scheduled surgery.³

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Sources

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.